It is known that blood sucking insects which feed on mammals are attracted to carbon dioxide gas. This is particularly true of the mosquito and tick. Since carbon dioxide is the end product of mammalian metabolism, it is presnt in mammalian blood and functions as a natural attractant for blood sucking insects.
The insect attracting property of carbon dioxide has been known for a number of years, and this property has been ultilized in combination with insect traps to increase the efficiency of a trap by attracting insects to the vicinity of the trap. The method previously used for releasing carbon dioxide in the vicinity of the trap has been to place solid carbon dioxide, or dry ice, near the trap to act as an attractant. As the solid carbon dioxide converts to the gaseous form, the carbon dioxide gas is released in the air around the trap attracting insects toward the trap.
The method of using dry ice, however, is both expensive and inconvenient in the field located trap. Common problems involved are storage and transportation of the dry ice as well as frequent baiting of the trap.